Electric storage device electrode and method for manufacturing same

Abstract

A method of manufacturing an energy storage device electrode in which breakage of electrode particles and warping of a collector are reduced, and internal resistance is lowered by lowering the contact resistance between the collector and an electrode layer. The method manufactures an electric double-layer capacitor electrode, and includes: forming a plurality of grooves that run in one direction in each of a front surface and rear surface of a collector foil; subsequently providing an electrode layer that includes plural electrode particles on each of the front surface and rear surface of the collector foil; and subsequently pressing the electrode layer toward the collector foil to move the plurality of electrode particles along the plurality of grooves until the plural electrode particles dig into the plurality of grooves.

The invention claimed is: 
     
       1. A method of manufacturing an energy storage device electrode, comprising:
 forming a plurality of grooves in a surface of a collector, wherein each of the grooves is elongated in one direction such that a longitudinal axis of each of the grooves is parallel to the surface of the collector and is shaped so that the respective groove is wider at one end of the respective groove than at another end of the respective groove in the one direction; 
 subsequently providing an electrode layer, which comprises a plurality of electrode particles, on the surface of the collector; and 
 subsequently pressing the electrode layer toward the collector to move the plurality of electrode particles along the plurality of grooves from the one end toward the another end until the plurality of electrode particles dig into the plurality of grooves. 
 
     
     
       2. A method of manufacturing an energy storage device electrode according to  claim 1 , wherein the forming of the plurality of grooves is performed by an embossing process. 
     
     
       3. A method of manufacturing an energy storage device electrode according to  claim 1 , wherein the forming of the plurality of grooves is performed by sanding with sandpaper or by hairline polishing. 
     
     
       4. A method of manufacturing an energy storage device electrode according to  claim 3 , wherein the forming of the plurality of grooves is performed in a manner that makes a minimum width value of the plurality of grooves smaller than a mean diameter of the plurality of electrode particles, and makes a mean width value of the plurality of grooves larger than the mean diameter of the plurality of electrode particles. 
     
     
       5. A method of manufacturing an energy storage device electrode according to  claim 1 , wherein the forming of the plurality of grooves is performed by moving the collector in the one direction while a groove forming roll, which has a plurality of projections on a circumferential surface, is kept in contact with the surface of the collector, and simultaneously rotating the groove forming roll in a direction that goes against a turning force generated in the groove forming roll by the movement of the collector. 
     
     
       6. A method of manufacturing an energy storage device electrode according to  claim 5 , wherein the groove forming roll is constructed by stacking alternately a plurality of toothed-edge disks, each of which has the plurality of projections formed on the circumferential surface, and a plurality of smooth-edge disks, each of which has a smoothly formed circumferential surface. 
     
     
       7. A method of manufacturing an energy storage device electrode according to  claim 1 , wherein the forming of the plurality of grooves is performed so that the plurality of grooves are formed in a middle portion of the surface of the collector. 
     
     
       8. A method of manufacturing an energy storage device electrode according to  claim 1 , further comprising:
 after the forming of the plurality of grooves in the surface of the collector, applying the electrode layer to the surface; and 
 subsequently reeling in the collector. 
 
     
     
       9. A method of manufacturing an energy storage device electrode according to  claim 1 , further comprising:
 after the forming of the plurality of grooves in the surface of the collector, removing a foreign material adhered to the surface; and 
 subsequently reeling in the collector after applying the electrode layer to the surface. 
 
     
     
       10. A method of manufacturing an energy storage device electrode according to  claim 1 , wherein inner walls of each of the grooves at the wider end have an arc shape as viewed from a direction perpendicular to the collector. 
     
     
       11. An energy storage device electrode, comprising:
 a collector having grooves formed in a surface thereof, wherein each of the grooves is elongated in one direction such that a longitudinal axis of each of the grooves is parallel to the surface of the collector and is shaped so that the respective groove is wider at one end of the respective groove than at another end of the respective groove in the one direction; and 
 an electrode layer provided on the surface of the collector and comprising electrode particles, which dig into the grooves at the another end.